Beam-combiner for fiber-delivered laser-beams of different wavelengths

Abstract

A beam combiner for combining laser-beams of different colors along a common path includes a directing-prism for each of the laser-beams and one combining-prism. The directing-prisms are arranged to transmit the laser-beams to the combining-prism. The directing-prisms and the combining-prism are configured and arranged with respect to each other such that the directing-prism transmits the beams along the common path.

What is claimed is: 
     
       1. Optical apparatus for combining at least a first plurality of laser-beams, each thereof having a different wavelength, the apparatus comprising:
 a first plurality of directing-prisms equal in number to the first plurality of laser-beams; 
 a combining-prism; 
 each of the plurality of directing-prisms being arranged to transmit a corresponding one of the first plurality of different-wavelength laser-beams directly therethrough without internal reflection and direct that laser-beam to the combining-prism; and 
 wherein the first plurality of directing-prisms and the combining-prism are configured and arranged such that the first plurality of different-wavelength laser-beams is transmitted by the combining-prism and exits the combining-prism along a common path. 
 
     
     
       2. The apparatus of  claim 1 , wherein the laser-beams are propagating parallel to each other prior to entering the directing-prisms and wherein the directing-prisms are arranged spaced apart with bases thereof about parallel to each other. 
     
     
       3. The apparatus of  claim 2 , wherein the base of the combining-prism is about parallel to the bases of the directing-prisms and the apex of the combining-prism is opposed to the apexes of the directing-prisms. 
     
     
       4. The apparatus of  claim 3 , wherein the laser-beams are incident on the directing-prisms and the combining-prism at about the minimum deviation angle for the directing prisms. 
     
     
       5. The apparatus of  claim 4 , wherein the directing prisms and the combining prism have the same dimensions and are made from the same material. 
     
     
       6. The apparatus of  claim 2 , wherein the laser-beams are about collimated before being transmitted by the directing-prisms. 
     
     
       7. The apparatus of  claim 1 , further including a plurality of input optical fibers corresponding in number to the plurality of laser-beams and each thereof transmitting a different one of the laser-beams toward a corresponding one of the plurality of directing prisms. 
     
     
       8. The apparatus of  claim 7 , further including a plurality of lenses each thereof arranged to collimate a corresponding one of the plurality of laser-beams transmitted by the optical fibers before the beams are transmitted by the plurality of directing-prisms. 
     
     
       9. The apparatus of  claim 8 , further including an output optical fiber and a focusing lens arranged to focus the laser-beams transmitted along the common path by the combining-prism into the output optical fiber. 
     
     
       10. The apparatus of  claim 9 , wherein the collimated laser-beams are propagating parallel to each other prior to entering the directing-prisms and wherein the directing-prisms are arranged spaced apart in a direction at angle to the laser-beams with bases thereof about parallel to each other. 
     
     
       11. The apparatus of  claim 10 , wherein the base of the combining-prism is about parallel to the bases of the directing-prisms and the apex of the combining-prism is opposed to the apexes of the directing-prisms. 
     
     
       12. The apparatus of  claim 11 , wherein the laser-beams are incident on the directing-prisms and the combining-prism at about the minimum deviation angle for the directing prisms. 
     
     
       13. The apparatus of  claim 12 , wherein the directing prisms and the combining prism have the same dimensions and are made from the same material. 
     
     
       14. Optical apparatus for combining first and second pluralities of laser-beams, each laser-beam having a different wavelength, the apparatus comprising:
 a first plurality of directing-prisms equal in number to the first plurality of laser-beams; 
 a second plurality of directing prisms, and a corresponding plurality of turning mirrors arranged as a plurality of prism-minor pairs, the prism-mirror pairs equal in number to the second plurality of laser-beams; 
 a combining prism; 
 each of the first plurality of directing-prisms being arranged to transmit a corresponding one of the first plurality of different-wavelength laser-beams and direct that laser-beam to the combining-prism; 
 each of the plurality of prism-mirror pairs being arranged to transmit a corresponding one of the second plurality of different-wavelength laser-beams and direct that laser-beam to the combining-prism; and wherein 
 the first plurality of directing prisms, the plurality of prism-minor pairs, and the combining-prism are configured and arranged such that the first and second pluralities of different-wavelength laser-beams are transmitted by the combining-prism, and exit the combining-prism along a common path. 
 
     
     
       15. The apparatus of  claim 14 , wherein the laser-beams in the first plurality thereof are propagating parallel to each other prior to entering the directing-prisms wherein the directing-prisms in the first plurality thereof are arranged spaced apart with bases thereof about parallel to each other. 
     
     
       16. The apparatus of  claim 15 , wherein the base of the combining-prism is about parallel to the bases of the first plurality of directing-prisms and the apex of the combining-prism is opposed to the apexes of the directing-prisms. 
     
     
       17. The apparatus of  claim 16 , wherein the laser-beams in the second plurality thereof are propagating parallel to the laser-beams in the first plurality of laser-beams. 
     
     
       18. The apparatus of  claim 14 , wherein the laser-beams in the second plurality thereof have wavelengths shorter than any of the wavelengths of the laser-beams in the first plurality thereof prior to entering the directing-prisms. 
     
     
       19. The apparatus of  claim 18  wherein the directing-prisms of the second plurality thereof are located closer to the combining-prism than directing-prisms of the first plurality thereof. 
     
     
       20. Optical apparatus for combining a plurality of parallel-propagating input laser-beams, the apparatus comprising:
 a plurality of pairs of spaced-apart, apex-opposed, directing-prisms corresponding in number to the plurality of input-laser-beams, and each thereof arranged to receive a corresponding one of the input laser-beams, and transmit that input laser-beam in a direction parallel to that in which it is received, such that the transmitted plurality of input laser-beams is parallel to the received plurality of input laser-beams; 
 a focusing lens and a combining prism; 
 the focusing lens arranged to receive the transmitted plurality of input laser-beams and converge the transmitted plurality of input laser-beams beams onto the combining prism; and 
 the combining-prism configured and arranged to transmit and combine the converged plurality of input laser-beams along a common path. 
 
     
     
       21. A method of combining laser beams, each beam having a different wavelength, said beams travelling along parallel paths, said method comprising:
 redirecting the beams along converging paths so that the beam intersect at a common location, said redirecting step being performed by transmitting each beam through an associated redirecting prism without internal reflection; and 
 combining the beams along a common path, said combining step being performed by a combining prism having an input face located at said common location. 
 
     
     
       22. A method as recited in  claim 21  wherein each beams passes through an apex of the associated redirecting prism and wherein the bases of the redirecting prisms are parallel. 
     
     
       23. A method as recited in  claim 22  wherein the base of the combining prism is parallel to the bases of the redirecting prisms and the apex of the combining prism is opposed to the apexes of the redirecting prisms.